White organic electroluminescent device and preparation method thereof

ABSTRACT

Provided is a white organic electroluminescent device, composed of a substrate, an anode layer, an anode modification layer, a hole transporting-electron blocking layer, a hole-dominated light-emitting layer, an electron-dominated light-emitting layer, a hole blocking-electron transporting layer, a cathode modification layer, and a cathode layer arranged in turn, wherein the electron-dominated light-emitting layer is composed of an organic sensitive material, a blue organic light-emitting material, and an electron-type organic host material. A rare earth complex having a matched energy level, such as Tm(acac)3Phen or Dy(acac)3phen is selected as the organic sensitive material, and a trace amount of the same is doped into the electron-dominated light-emitting layer, which has the function of an energy transporting ladder and a deep binding center for charge carriers, so as to improve the light-emitting effectiveness, spectral stability, and service life of the device, reduce the operating voltage of the device, and delay the attenuation of the effectiveness of the device.

This application claims the priority of Chinese Patent Application No.201410605604.9, filed with SIPO on Oct. 30, 2014, entitled “WHITEORGANIC ELECTROLUMINESCENT DEVICE AND PREPARATION METHOD THEREOF”, theentire contents of which are incorporated in this application byreference.

FIELD OF THE INVENTION

This invention relates to the technical field of organicelectroluminescence, and particularly to a white organicelectroluminescent device and the preparation method thereof.

BACKGROUND OF THE INVENTION

An organic electroluminescent device is a device which spontaneouslyemits light, and the principle of light emission thereof is as follows.When charges are injected into an organic layer between a hole injectionelectrode and an electron injection electrode, electrons and holesencounter, combined, and then annihilated, and thus light is generated.Organic electroluminescent devices have the characteristics of lowvoltage, high brightness, wide view angle, or the like. Therefore,organic electroluminescent devices have been rapidly developed in recentyears. Among these, the white organic electroluminescent devices havebecome hot spots of investigation due to the wide prospect forapplication in terms of display, illumination, or the like.

Trivalent iridium complexes are considered as ideal organicelectroluminescent materials in both the academic world and theindustrial world all the time due to the advantages of highlight-emitting effectiveness, adjustable color of light emission, or thelike. A number of domestic and foreign research teams have intended toimprove the overall properties of the white organic electroluminescentdevices by starting with aspects of material synthesis and deviceoptimization so as to meet the requirement for industrialization. ForExample, in 2006, Forrest et al at Princeton University in United Statesdesigned a white organic electroluminescent device having a structurewith multiple light-emitting layers, by doping a blue light material, agreen light material and a red light material in differentlight-emitting layers respectively. Although that device exhibitsrelatively ideal white light emission, the device has relatively lowefficiency and brightness and relatively high working voltage, due tounbalanced carrier injection. Additionally, complex structure of thedevice further results in relatively high manufacturing cost of thedevice

In order to solve these problems, in 2008, Kido et al at YamagataUniversity in Japan designed a structure of device having doublelight-emitting layers, to combine a blue-green light and an orange-redlight, so as to obtain a white-light-emitting device successfully. Thatdevice has relatively high light-emitting effectiveness, but the featureof double-peak emission results in that the spectrum of the device doesnot have enough coverage degree in the white-light region, and thus thecolor restoration coefficient is relatively low. Further, as thebrightness of the luminescence increases, the emission spectrum of thedevice varies greatly. As thus can be seen, the overall properties, suchas light-emitting effectiveness, brightness, spectral stability, servicelife, and the like, of the white organic electroluminescent device arestill not effectively improved.

SUMMARY OR THE INVENTION

The technical problem to be solved by this invention is to provide awhite organic electroluminescent device having relatively high overallproperties and the preparation method thereof.

In view of this, this application provides a white organicelectroluminescent device, comprising:

a substrate:

an anode layer provided on the substrate;

an anode modification layer provided on the anode layer;

a hole transporting-electron blocking layer provided on the anodemodification layer;

a hole-dominated light-emitting layer provided on the holetransporting-electron blocking layer;

an electron-dominated light-emitting layer provided on thehole-dominated light-emitting layer;

a hole blocking-electron transporting layer provided on theelectron-dominated light-emitting layer;

a cathode modification layer provided on the hole blocking-electrontransporting layer; and

a cathode layer provided on the cathode modification layer;

wherein the electron-dominated light-emitting layer is composed of anorganic sensitive material, a blue organic light-emitting material, andan electron-type organic host material;

the hole-dominated light-emitting layer is composed of a green organiclight-emitting material, a red organic light-emitting material and ahole-type organic host material,

the organic sensitive material is one or two selected fromtris(acetylacetone)phenanthroline thulium andtris(acetylacetone)phenanthroline dysprosium; and

the organic sensitive material is 0.1 wt %-0.5 wt % of the electron-typeorganic host material.

Preferably, the content of the blue organic light-emitting material is8.0 wt %-25.0 wt % of the content of the electron-type organic hostmaterial.

Preferably, the blue organic light-emitting material is one or moreselected from bis((3,5-difluoro-4-cyanophenyl)pyridinato)picolinateiridium, bis(2,4-difluorophenylpyridinato)tetrakis(1-pyrazolyl)borateiridium, tris(1-phenyl-3-methylbenzimidazolin-2-ylidene-C,C2′) iridium,tris(1-phenyl-3-methylbenzimidazolin-2-ylidene-C,C2′) iridium,bis(2,4-difluorophenylpyridinato)(5-(pyridin-2-yl)-1H-tetrazolate)iridium,tris[(2,6-diisopropylphenyl)-2-phenyl-1H-imidazol[e]iridium,tris(1-phenyl-3-methylimidazolin-2-ylidene-C,C(2)′)iridium,tris(1-phenyl-3-methylimidazolin-2-ylidene-C,C(2)′)iridium,bis(1-phenyl-3-methylimdazolin-2-ylidene-C,C²′)(2-(2H-pyrazol-3-yl)-pyridine)iridium,bis(1-(4-methylphenyl)-3-methylimdazolin-2-ylidene-C,C²′)(2-(2H-pyrazol-3-yl)-pyridine)iridium,bis(1-(4-fluorophenyl)-3-methylimdazoline-2-ylidene-C,C²′)(2-(2H-pyrazol-3-yl)-pyridine)iridium,bis(1-(4-fluorophenyl)-3-methylimdazoline-2-ylidene-C,C²′)(2-(5-trifluoromethyl-2H-pyrazol-3-yl)-pyridine)iridium,tris(1,3-diphenyl-benzimidazolin-2-ylidene-C,C²′)iridium,bis(1-(4-fluorophenyl)-3-methylimdazoline-2-ylidene-C,C²′)(3,5-dimethyl-2-(1H-pyrazol-5-yl)pyridine)iridium,bis(1-(4-methylphenyl)-3-methylimdazolin-2-ylidene-C,C²′)(3,5-dimethyl-2-(1H-pyrazol-5-yl)pyridine)iridium,and tris(phenylpyrazole)iridium.

Preferably, the electron-type organic host material is one or moreselected from 2,6-bis[3-(9H-9-carbazoyl)phenyl]pyridine,1,4-bis(triphenylsilyl)benzene, 2,2′-bis(4-(9-carbazoyl)phenyl)biphenyl,tris[2,4,6-trimethyl-3-(3-pyridinyl)phenyl]borane,1,3,5-tri[(3-pyridinyl)-3-phenyl]benzene,1,3-bis[3,5-di(3-pyridinyl)phenyl]benzene,1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene,9-(4-tert-butylphenyl)-3,6-bis(triphenylsilyl)-9H-carbazole, and9-(8-diphenylphosphoryl)-dibenzo[b, d]furan-9H-carbazole.

Preferably, the red organic light-emitting material is 1.0 wt %-3.0 wt %of the hole-type organic host material; the green organic light-emittingmaterial is 5.0 wt %-10.0 wt %0 of the hole-type organic host material;

the green organic light-emitting material is one or more selected fromtris(2-phenylpyridine) iridium, bis(2-phenylpyridine)(acetylacetone)iridium, tris[2-(p-tolyl)pyridine]iridium,bis(2-phenylpyridine)[2-(diphen-3-yl)pyridine]iridium,tris(2-(3-paraxylene)pyridine iridium andtris(2-phenyl-3-methyl-pyridine) iridium,

the red organic light-emitting material is one or more selected frombis(2-phenylquinoline)-(2,2,6,6-tetramethyl-3,5-heptanedionate) iridium,bis(2-benzo[b]-2-thiophenyl-pyridine)acetylacetone) iridium,tris(1-phenylisoquinoline) iridium,bis(1-phenylisoquinoline)acetylacetone) iridium,bis[1-(9,9-dimethyl-9H-fluoren-2-yl)-isoquinoline](acetylacetone)iridium, bis[2-(9,9-dimethyl-9H-fluoren-2-yl)-quinoline](acetylacetone)iridium, bis(2-phenylquinoline)(2-(3-tolyl)pyridine) iridium,tris[2-phenyl-4-methylquinoline]iridium,bis(phenylisoquinoline)(2,2,6,6-tetramethylhexane-3,5-dione) iridium,bis(2-methyldibenzo[f,h]quinoxaline)(acetylacetone) iridium, andbis[2-(2-methylphenyl)-7-methyl-quinoline](acetylacetone) iridium, and

the hole-type organic host material is one or more selected from4,4′-N,N′-dicarbazole-biphenyl, 1,3-dicarbazol-9-ylbenzene,9,9′-(5-(triphenylsilyl)-1,3-phenyl)bis-9H-carbazole,1,3,5-tris(9-carbazoyl)benzene,4,4′,4″-tris(carbazol-9-yl)triphenylamine, and1,4-bis(triphenylsilyl)biphenyl.

Preferably, the material of the hole transporting-electron blockinglayer is one or more selected from4,4′-cyclohexylidenebis[N,N-bis(4-methylphenyl)aniline],dipyrazino[2,3-f:2′,3′-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile,N4,N4′-di(naphthalene-1-yl)-N4,N4′-bis(4-vinylphenyl)biphenyl-4,4′-diamine,N,N′-bis(3-methylphenyl)-N,N′-bis(phenyl)-2,7-diamino-9,9-spirobifluorene,N,N,N′,N′-tetra-(3-methylphenyl)-3-3′-dimethylbenzidine,2,2′-bis(3-(N,N-di-p-tolylamino)phenyl)biphenyl.N,N′-bis(naphthalen-2-yl)-N,N′-bis(phenyl)benzidine,N,N′-bis(naphthalen-1-yl)-N,N′-diphenyl-2,7-diamino-9,9-spirobifluorene,N,N′-bis(3-methylphenyl)-N,N′-diphenyl-2,7-diamino-9,9-dimethylfluorene,N,N′-bis(naphthalen-1-yl)-N,N′-diphenyl-2,7-diamino-9,9-dimethylfluorene.N,N′-bis(3-methylphenyl)-N,N′-diphenyl-2,7-diamino-9,9-diphenylfluorene,N,N′-bis(naphthalen-1-yl)-N,N′-diphenyl-2,7-diamino-9,9-diphenylfluorene.N,N′-bis(naphthalen-1-yl)-N,N′-diphenyl-2,2′-dimethylbenzidine,2,2′,7,7′-tetrakis(N,N-diphenylamino)-2,7-diamino-9,9-spirobifluorene,9,9-bis[4-(N,N-bis-naphthalen-2-yl-amino)phenyl]-9H-fluorene,9.9-[4-(N-naphthalen-1-yl-N-anilino)-phenyl]-9H-fluorene,2,2′-bis[N,N-bis(4-phenyl)amino]-9,9-spirobifluorene,2,2′-bis(N,N-phenylamino)-9,9-spirobifluorene,N,N′-diphenyl-N,N′-(1-naphthyl)-1,1′-biphenyl-4,4′-diamine, and4,4′-bis[N-(p-tolyl)-N-phenyl-amino]diphenyl.

Preferably, the material of the hole blocking-electron transportinglayer is one or more selected fromtris[2,4,6-trimethyl-3-(3-pyridinyl)phenyl]borane,1,3,5-tri[(3-pyridinyl)-3-phenyl]benzene,1,3-bis[3,5-di(3-pyridinyl)phenyl]benzene, and1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene.

Preferably, the anode modification layer has a thickness of 1-10 nm, thehole transporting-electron blocking layer has a thickness of 30-60 nm,the hole-dominated light-emitting layer has a thickness of 5-20 nm, theelectron-dominated light-emitting layer has a thickness of 5-20 nm, thehole blocking-electron transporting layer has a thickness of 30-60 nm,the cathode modification layer has a thickness of 0.8-1.2 nm, and thecathode layer has a thickness of 90-300 nm.

This application further provides a preparation method of a whiteorganic electroluminescent device, comprising the steps of:

etching an anode layer on a substrate, and after drying, evaporationplating an anode modification layer, a hole transporting-electronblocking layer, a hole-dominated light-emitting layer, anelectron-dominated light-emitting layer, a hole blocking-electrontransporting layer, a cathode modification layer, and a cathode layer inturn on the anode layer,

wherein a material of the electron-dominated light-emitting layer iscomposed of an organic sensitive material, a blue organic light-emittingmaterial, and an electron-type organic host material;

the organic sensitive material is one or two selected fromtris(acetylacetone)phenanthroline thulium andtris(acetylacetone)phenanthroline dysprosium; and

the organic sensitive material is 0.1 wt %-0.5 wt % of the electron-typeorganic host material.

Preferably, the evaporation plating rate for the anode modificationlayer is 0.01-0.05 nm/s; the evaporation plating rates for the hostmaterials in the hole transporting-electron blocking layer, thehole-dominated light-emitting layer, the electron-dominatedlight-emitting layer, and the hole blocking-electron transporting layerare 0.05-0.1 nm/s; the evaporation plating rate for the organicsensitized material in the electron-dominated light-emitting layer is0.00005-0.0005 nm/s; the evaporation plating rate for the blue organiclight-emitting material in the electron-dominated light-emitting layeris 0.004-0.025 nm/s; the evaporation plating rate for the redlight-emitting material in the hole-dominated light-emitting layer is0.0005-0.003 nm/s; the evaporation plating rate for the green organiclight-emitting materials in the hole-dominated light-emitting layer is0.0025-0.01 nm/s; the evaporation plating rate for the cathodemodification layer is 0.005-0.05 nm/s; and the evaporation plating ratefor the cathode layer is 0.5-2.0 nm/s.

This application provides a white organic electroluminescent device,comprising: a substrate, an anode layer, an anode modification layer, ahole transporting-electron blocking layer, a hole-dominatedlight-emitting layer, an electron-dominated light-emitting layer, a holeblocking-electron transporting layer, a cathode modification layer, anda cathode layer. The light-emitting materials of this application are ablue light-emitting material, a green light-emitting material, and a redlight-emitting material. When an electron and a hole are injected into alight-emitting layer respectively, the electron and the hole willencounter and be recombined to generate an exciton. The exciton willtransfer the energy to a molecule of the light-emitting material in thelight-emitting layer to excite an electron into the excited state. Aphoton will be generated when the electron in the excited state returnsto the ground state in a manner of radiative transition. Thelight-emitting layers of the organic electroluminescent device containlight-emitting materials for the three primary colors, i.e. red, greenand blue. When the doping concentrations of the light-emitting materialsfor the three colors come to an effective formulation, the proportion ofthe photons of these three colors will reach a balanced distributionclose to the sunlight, and thereby white light emission occurs.

In this application, by adding one or two oftris(acetylacetone)phenanthroline thulium andtris(acetylacetone)phenanthroline dysprosium to the electron-dominatedlight-emitting layer as an organic sensitive material. Since the energylevel and the triplet energy thereof match the energy levels and thetriplet energies of the electron-type host material and the bluelight-emitting material, so that the organic sensitive material has thefunction of an energy transporting ladder and a deep binding center forcharge carriers in the process of electroluminescence. This not onlyimproves the energy transfer from the host material to thelight-emitting material, but also balances the distribution of electronsand holes in the range of light emission. Therefore, the light-emittingeffectiveness of the organic electroluminescent device is improved, thespectral stability of the device is improved, the operating voltage ofthe device is reduced, the efficiency attenuation of the device isdelayed, and the service life of the device is improved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a structural schematic diagram of the white organicelectroluminescent device of this invention;

FIG. 2 is a plot of the characteristics of voltage-currentdensity-brightness of the white organic electroluminescent deviceprepared in Example 1 of this invention;

FIG. 3 is a plot of the characteristics of current density-powerefficiency-current efficiency of the white organic electroluminescentdevice prepared in Example 1 of this invention; and

FIG. 4 is a spectrogram of the white organic electroluminescent deviceprepared in Example 1 of this invention when the brightness is 20000cd/m².

DETAILED DESCRIPTION OF THE INVENTION

In order to further understand this invention, the preferred embodimentsof this invention are described below in conjunction with Examples.However, it is to be understood that these descriptions are only used tofurther illustrate characteristics and advantages of this invention, andare not limitations to the claims of this invention.

An embodiment of this invention discloses a white organicelectroluminescent device, comprising:

a substrate;

an anode layer provided on the substrate:

an anode modification layer provided on the anode layer:

a hole transporting-electron blocking layer provided on the anodemodification layer;

a hole-dominated light-emitting layer provided on the holetransporting-electron blocking layer;

an electron-dominated light-emitting layer provided on thehole-dominated light-emitting layer:

a hole blocking-electron transporting layer provided on theelectron-dominated light-emitting layer;

a cathode modification layer provided on the hole blocking-electrontransporting layer; and

a cathode layer provided on the cathode modification layer;

wherein the electron-dominated light-emitting layer is composed of anorganic sensitive material, a blue organic light-emitting material, andan electron-type organic host material;

the organic sensitive material is one or two selected fromtris(acetylacetone)phenanthroline thulium andtris(acetylacetone)phenanthroline dysprosium; and

the organic sensitive material is 0.1 wt %-0.5 wt % of the electron-typeorganic host material.

The principle of light emission of an organic electroluminescent device(OLED) is the phenomenon that an electron and a hole injected throughelectrodes encounter in an organic matter under the driving of anexternal voltage and the energy is transferred to an organiclight-emitting molecule, which is excited to transit from the groundstate to the excited state, and light emission is generated by theradiative transition when the excited molecule returns from the excitedstate to the ground state. This application provides a white organicelectroluminescent device. When an electron and a hole are injected intoa light-emitting layer respectively, the electron and the hole willencounter and be recombined to generate an exciton. The excitontransfers the energy to a molecule of the light-emitting material in thelight-emitting layer to excite an electron into the excited state. Aphoton will be generated when the electron in the excited state returnsto the ground state in a manner of transition. Since the light-emittinglayers contain light-emitting materials for the three primary colors,i.e. red, green and blue, when the doping concentrations of thelight-emitting materials for the three colors come to an effectiveformulation, the proportion of the photons of these three colors willreach a balanced distribution close to the sunlight, and thereby whitelight emission occurs.

The white organic electroluminescent device of this application iscomposed of a substrate, an anode layer, an anode modification layer, ahole transporting-electron blocking layer, a hole-dominatedlight-emitting layer, an electron-dominated light-emitting layer, a holeblocking-electron transporting layer, a cathode modification layer, anda cathode layer connected in turn. Here, the hole-dominatedlight-emitting layer and the electron-dominated light-emitting layer arethe light-emitting layers of the white organic electronic light-emittingdevice.

The electron-dominated light-emitting layer of this invention iscomposed of an organic sensitive material, a blue organic light-emittingmaterial, and an electron-type organic host material, wherein theorganic sensitive material exerts an effect of sensitization in theprocess of electroluminescence to balance the distribution of electronsand holes in the range of light emission and improve the energy transferfrom the host material to the light-emitting material; the molecules ofthe blue organic light-emitting material are dispersed in theelectron-dominated light-emitting layer as luminescent centers; and theelectron-type organic host material acts as a base material to providethe electron transporting capability. In the electron-dominatedlight-emitting layer, the energy level and the triplet energy of theorganic sensitive material are required to match the energy levels andthe triplet energies of the host material and the light-emittingmaterial so as to balance the distribution of electrons and holes in therange of light emission and accelerate the energy transfer from the hostmaterial to the light-emitting material, so that the white organicelectroluminescent device has good overall properties. Therefore, by theselection of the light-emitting material in this application, a rareearth complex having matched energy in energy levels is selected as theorganic sensitive material. The organic sensitive material is one or twoselected from tris(acetylacetone)phenanthroline thulium (Tm(acac)₃phen)having the structure of formula (IX) andtris(acetylacetone)phenanthroline dysprosium (Dy(acac)₃phen) having thestructure of formula (X):

In this invention, the doping concentration of the organic sensitivematerial in the electron-dominated light-emitting layer influences theproperties of the organic electroluminescent device. If the dopingconcentration of the organic sensitive material is too low, anundesirable effect of sensitization will be caused. If the dopingconcentration is too high, the overall properties of luminescence of theorganic electroluminescent device will be reduced. Therefore, theorganic sensitive material is 0.1 wt %-0.5 wt %, preferably 0.2 wt %-0.3wt % of the electron-type organic host material.

According to this invention, organic light-emitting materials of thethree primary colors are contained respectively in theelectron-dominated light-emitting layer and the hole-dominatedlight-emitting layer, so that the organic electroluminescent device canemit white light. The organic light-emitting material in theelectron-dominated light-emitting layer is a blue light-emittingmaterial, the blue organic light-emitting material in theelectron-dominated light-emitting layer is a light-emitting materialwhich is well known by the person skilled in the art, and is notparticularly limited in this application. However, in order for a bettereffect of light emission, the blue organic light-emitting material ispreferably one or more selected frombis((3,5-difluoro-4-cyanophenyl)pyridinato)picolinate iridium (FCNIrpic)having the structure of formula (II₁),bis(2,4-difluorophenylpyridinato)tetrakis(1-pyrazolyl)borate iridium(Fir6) having the structure of formula (II₂), fac-Iridiumtris(1-phenyl-3-methylbenzimidazolin-2-ylidene-C,C2′) (fac-Ir(pmb)₃)having the structure of formula (II₃), mer-Iridiumtris(1-phenyl-3-methylbenzimidazolin-2-ylidene-C,C2′) (mer-Ir(Pmb)₃)having the structure of formula (II₄),bis(2,4-difluorophenylpyridinato)(5-(pyridin-2-yl)-1H-tetrazolate)iridium(FIrN4) having the structure of formula (II₅),fac-tris[(2,6-diisopropylphenyl)-2-phenyl-1H-imidazol[e]iridium(fac-Ir(iprpmi)₃) having the structure of formula (II₆),fac-tris(1-phenyl-3-methylimidazolin-2-ylidene-C,C(2)′)iridium(fac-Ir(pmi)₃) having the structure of formula (II₇),mer-tris(1-phenyl-3-methylimidazolin-2-ylidene-C,C(2)′)iridium(mer-Ir(pmi)₃) having the structure of formula (II₈),bis(1-phenyl-3-methylimdazolin-2-ylidene-C,C²′)(2-(2H-pyrazol-3-yl)-pyridine)iridium((pmi)₂Ir(pypz)) having the structure of formula (II₉),bis(1-(4-methylphenyl)-3-methylimdazolin-2-ylidene-C,C²′)(2-(2H-pyrazol-3-yl)-pyridine)iridium((mpmi)₂Ir(pypz)) having the structure of formula (II₁₀),bis(1-(4-fluorophenyl)-3-methylimdazoline-2-ylidene-C,C²′)(2-(2H-pyrazol-3-yl)-pyridine)iridium((fpmi)₂Ir(pypz)) having the structure of formula (II₁₁),bis(1-(4-fluorophenyl)-3-methylimdazoline-2-ylidene-C,C²′)(2-(5-trifluoromethyl-2H-pyrazol-3-yl)-pyridine)iridium((fpmi)₂Ir(tfpypz)) having the structure of formula (II₁₂),fac-tris(1,3-diphenyl-benzimidazolin-2-ylidene-C,C²′)iridium(fac-Ir(dpbic)₃) having the structure of formula (II₁₃),bis(1-(4-fluorophenyl)-3-methylimdazoline-2-ylidene-C,C²′)(3,5-dimethyl-2-(1H-pyrazol-5-yl)pyridine)iridium((fpmi)₂Ir(dmpypz)) having the structure of formula (II₁₄),bis(1-(4-methylphenyl)-3-methylimdazolin-2-ylidene-C,C²′)(3,5-dimethyl-2-(1H-pyrazol-5-yl)pyridine)iridium((mpmi)₂Ir(dmpypz)) having the structure of formula (II₁₅) andtris(phenylpyrazole)iridium (Ir(ppz)₃) having the structure of formula(II₆):

In the electron-dominated light-emitting layer, the doping concentrationof the blue organic light-emitting material may also influence theoverall properties of the white organic electroluminescent device. Ifthe doping concentration of the blue organic light-emitting material istoo low, relatively low efficiency and undesirable spectral stability ofthe device will be caused. If the doping concentration is too high, theagglomeration of molecules of the light-emitting material and theformation of quenching centers will be caused, and the overallproperties of the device are finally reduced. Therefore, the dopingconcentration of the blue organic light-emitting material is preferably8.0 wt %-25.0 wt %, more preferably 10.0 wt %-20.0 wt %, and mostpreferably 15.0 wt %-18.0 wt % of the electron-type organic hostmaterial. The electron-type host material in the electron-dominatedlight-emitting layer acts as a base material to provide the electrontransporting capability. The electron-type host material is a materialwhich is well known by the person skilled in the art. As a preferredembodiment, the electron-type host material is preferably one or moreselected from 2,6-bis[3-(9H-9-carbazoyl)phenyl]pyridine (26DCzPPy)having the structure of formula (XI), 1,4-bis(triphenylsilyl)benzene(UGH2) having the structure of formula (XII),2,2′-bis(4-(9-carbazoyl)phenyl)biphenyl (BCBP) having the structure offormula (XIII), tris[2,4,6-trimethyl-3-(pyridin-3-yl)phenyl]borane(3TPYMB) having the structure of formula (XIV),1,3,5-tri[(3-pyridinyl)-3-phenyl]benzene (TmPvPB) having the structureof formula (XV), 1,3-bis[3,5-di(3-pyridinyl)phenyl]benzene (BmPyPhB)having the structure of formula (XVI),1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene (TPBi) having thestructure of formula (XVII),9-(4-tert-butylphenyl)-3,6-bis(triphenylsilyl)-9H-carbazole (CzSi)having the structure of formula (XVIII), and9-(8-diphenylphosphoryl)-dibenzo[b, d]furan-9H-carbazole (DFCzPO) havingthe structure of formula (XIX):

In this application, materials in the hole-dominated light-emittinglayer are a red organic light-emitting material, a green organiclight-emitting material, and a hole-type organic host material, whereinthe molecules of the green organic light-emitting material and the redorganic light-emitting material are dispersed in the hole-dominatedlight-emitting layer as luminescent centers. The organic light-emittingmaterials include a red organic light-emitting material, a green organiclight-emitting material and a blue organic light-emitting material. Inthis application; the organic light-emitting material in theelectron-dominated light-emitting layer is a blue light-emittingmaterial, and the light-emitting materials in the hole-dominatedlight-emitting layer are a red organic light-emitting material and agreen organic light-emitting material. The configuration of thelight-emitting materials of different colors can improve the colorrestoration coefficient of the device and ensure the spectral stabilityof the device effectively. The red organic light-emitting material ispreferably 1.0 wt %-3.0 wt % of the hole-type organic host material, andthe green organic light-emitting material is preferably 5.0 wt %-10.0 wt% of the hole-type organic host material. If the doping concentration ofthe organic light-emitting material is too low, relatively lowefficiency and undesirable spectral stability of the device will becaused. If the doping concentration is too high, the agglomeration ofmolecules of the light-emitting material and the formation of quenchingcenters will be caused, and the overall properties of the device arefinally reduced. The hole-type host material acts as a base material toprovide the hole transporting capability. In this application, in thehole-dominated light-emitting layer, the green organic light-emittingmaterial is preferably one or more selected from tris(2-phenylpyridine)iridium (Ir(ppy)₃) having the structure of formula (II₁₇),bis(2-phenylpyridine)(acetylacetone) iridium (Ir(ppy)₂(acac)) having thestructure of formula (II₁₈), tris[2-(p-tolyl)pyridine]iridium(Ir(mppy)₃) having the structure of formula (II₁₉),bis(2-phenylpyridine)[2-(diphen-3-yl)pyridine]iridium (Ir(ppy)₂(m-bppy))having the structure of formula (II₂₀), tris(2-(3-paraxylene)pyridineiridium (TEG) having the structure of formula (II₂₁) andtris(2-phenyl-3-methyl-pyridine) iridium (Ir(3mppy)₃) having thestructure of formula (II₂₂);

the red organic light-emitting material is preferably one or moreselected frombis(2-phenylquinoline)-(2,2,6,6-tetramethyl-3,5-heptanedionate) iridium(PQ₂Ir(dpm)) having the structure of formula (II₂₃),bis(2-benzo[b]-2-thiophenyl-pyridine)(acetylacetonate) iridium(Ir(btp)₂(acac)) having the structure of formula (II₂₄),tris(1-phenylisoquinoline) iridium (Ir(piq)₃) having the structure offormula (II₂₅), bis(1-phenylisoquinoline)(acetylacetone) iridium(Ir(piq)₂(acac)) having the structure of formula (II₂₆),bis[1-(9,9-dimethyl-9H-fluoren-2-yl)-isoquinoline](acetylacetone)iridium (Ir(fliq)₂(acac)) having the structure of formula (II₂₇),bis[2-(9,9-dimethyl-9H-fluoren-2-yl)-quinoline](acetylacetone) iridium(Ir(flq)₂(acac)) having the structure of formula (II₂₈),bis(2-phenylquinoline)(2-(3-tolyl)pyridine) iridium (Ir(phq)₂tpy) havingthe structure of formula (II₂₉), tris[2-phenyl-4-methylquinoline]iridium(Ir(Mphq)₃) having the structure of formula (II₃₀),bis(phenylisoquinoline)(2,2,6,6-tetramethylhexane-3,5-dione) iridium(Ir(dpm)(piq)₂) having the structure of formula (II₃₁),bis(2-methyldibenzo[f,h]quinoxaline)(acetylacetone) iridium(Ir(MDQ)₂(acac)) having the structure of formula (II₃₂), andbis[2-(2-methylphenyl)-7-methyl-quinoline](acetylacetone) iridium(Ir(dmpq)₂(acac)) having the structure of formula (II₃₃);

the hole-type organic host material is preferably one or more selectedfrom 4,4′-N,N′-dicarbazole-biphenyl (CBP) having the structure offormula (III), 1,3-dicarbazol-9-ylbenzene (mCP) having the structure offormula (IV), 9,9′-(5-(triphenylsilyl)-1,3-phenyl)bis-9H-carbazole(SimCP) having the structure of formula (V),1,3,5-tris(9-carbazoyl)benzene (TCP) having the structure of formula(VI), 4,4′,4″-tris(carbazol-9-yl)triphenylamine (TcTa) having thestructure of formula (VII), and 1,4-bis(triphenylsilyl)biphenyl (BSB)having the structure of formula (VIII).

According to this invention, in the white organic electroluminescentdevice, the substrate may be a glass substrate, a quartz substrate, apolycrystalline silicon substrate, a monocrystalline silicon substrate,or a graphene thin-film substrate, and is not particularly limited inthis application. The anode layer is preferably selected from indium tinoxide (ITO), which has a surface resistance of preferably 5-25Ω. Theanode modification layer may reduce the drive voltage and accelerate thehole injection. Molybdenum oxide (MoO₃) is preferably used for the anodemodification layer.

In this application, the function of the hole transporting-electronblocking layer is transporting holes and blocking electrons. Thematerial of the hole transporting-electron blocking layer is preferablyone or more selected from4,4′-cyclohexylidenebis[N,N-bis(4-methylphenyl)aniline] (TAPC) havingthe structure of formula (I₁),dipyrazino[2,3-f:2′,3′-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile(HAT-CN) having the structure of formula (I₂).N4,N4′-di(naphthalene-1-yl)-N4,N4′-bis(4-vinylphenyl)biphenyl-4,4′-diamine(VNPB) having the structure of formula (I₃),N,N′-bis(3-methylphenyl)-N,N′-bis(phenyl)-2,7-diamino-9,9-spirobifluorene(Spiro-TPD) having the structure of formula (I₄),N,N,N′,N′-tetra-(3-methylphenyl)-3-3′-dimethylbenzidine (HMTPD) havingthe structure of formula (I₅),2,2′-bis(3-(N,N-di-p-tolylamino)phenyl)biphenyl (3DTAPBP) having thestructure of formula (I₆).N,N′-bis(naphthalen-2-yl)-N,N′-bis(phenyl)benzidine (β-NPB) having thestructure of formula (I₇),N,N′-bis(naphthalen-1-yl)-N,N′-diphenyl-2,7-diamino-9,9-spirobifluorene(Spiro-NPB) having the structure of formula (I₈),N,N′-bis(3-methylphenyl)-N,N′-diphenyl-2,7-diamino-9,9-dimethylfluorene(DMFL-TPD) having the structure of formula (I₉),N,N′-bis(naphthalen-1-yl)-N,N′-diphenyl-2,7-diamino-9,9-dimethylfluorene(DMFL-NPB) having the structure of formula (I₁₀),N,N′-bis(3-methylphenyl)-N,N′-diphenyl-2,7-diamino-9,9-diphenylfluorene(DPFL-TPD) having the structure of formula (In),N,N′-bis(naphthalen-1-yl)-N,N′-diphenyl-2,7-diamino-9,9-diphenylfluorene(DPFL-NPB) having the structure of formula (I₁₂),N,N′-bis(naphthalen-1-yl)-N,N′-diphenyl-2,2′-dimethylbenzidine (α-NPD)having the structure of formula (II₃),2,2′,7,7′-tetrakis(N,N-diphenylamino)-2,7-diamino-9,9-spirobifluorene(Spiro-TAD) having the structure of formula (I₁₄),9,9-bis[4-(N,N-bis-naphthalen-2-yl-amino)phenyl]-9H-fluorene (NPAPF)having the structure of formula (I₁₅),9,9-[4-(N-naphthalen-1-yl-N-anilino)-phenyl]-9H-fluorene (NPBAPF) havingthe structure of formula (I₁₆),2,2′-bis[N,N-bis(4-phenyl)amino]-9,9-spirobifluorene (2,2′-Spiro-DBP)having the structure of formula (I₁₇),2,2′-bis(N,N-phenylamino)-9,9-spirobifluorene (Spiro-BPA) having thestructure of formula (I₁₈),N,N′-diphenyl-N,N′-(1-naphthyl)-1,1′-biphenyl-4,4′-diamine (NPB) havingthe structure of formula (I₁₉), and4,4-bis[N-(p-tolyl)-N-phenyl-amino]diphenyl (TPD) having the structureof formula (I₂₀).

According to this invention, the function of the hole blocking-electrontransporting layer is transporting electrons and blocking holes topromote the electron injection. The material of the holeblocking-electron transporting layer is preferably one or more selectedfrom tris[2,4,6-trimethyl-3-(3-pyridinyl)phenyl]borane (3TPYMB) havingthe structure of formula (XIV), 1,3,5-tri[(3-pyridinyl)-3-phenyl]benzene(TmPyMB) having the structure of formula (XV),1,3-bis[3,5-di(3-pyridinyl)phenyl]benzene (BmPyPhB) having the structureof formula (XVI), and 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene(TPBi) having the structure of formula (XVII):

In this application, the function of the cathode modification layer isreducing the drive voltage and accelerating the electron injection. Thecathode modification layer is preferably lithium fluoride. The cathodelayer is preferably aluminum.

In this application, the sources of the material of the holetransporting-electron blocking layer, the blue organic light-emittingmaterial, the red organic light-emitting material, the yellow organiclight-emitting material, the hole-type organic host material, theorganic sensitive material, the electron-type organic host material, andthe material of the hole blocking-electron transporting layer are notparticularly limited, and they may be obtained by the preparation in amanner well known by the person skilled in the art.

In this application, the anode layer and the cathode layer areoverlapped with each other to form a light-emitting zone. The thicknessof each layer in the white organic electroluminescent device of thisapplication has significant effect on the device. If the thickness istoo small, it will result in faster attenuation of the deviceefficiency. If the thickness is too large, it will result in highoperating voltage and short service life of the device. Therefore, thethickness of the anode modification layer is preferably 1-10 nm, thethickness of the hole transporting-electron blocking layer is preferably30-60 nm, the thickness of the hole-dominated light-emitting layer ispreferably 5-20 nm, the thickness of the electron-dominatedlight-emitting layer is preferably 5-20 nm, the thickness of the holeblocking-electron transporting layer is preferably 30-60 nm, thethickness of the cathode modification layer is preferably 0.8-1.2 nm,and the thickness of the cathode layer is preferably 90-300 nm.

This application further provides a preparation method of the whiteorganic electroluminescent device, comprising the steps of:

etching an anode layer on a substrate, and after drying, evaporationplating an anode modification layer, a hole transporting-electronblocking layer, a hole-dominated light-emitting layer, anelectron-dominated light-emitting layer, a hole blocking-electrontransporting layer, a cathode modification layer, and a cathode layer inturn on the anode layer,

wherein the electron-dominated light-emitting layer is formed by mixingan organic sensitive material, a blue organic light-emitting material,and an electron-type organic host material;

wherein the hole-dominated light-emitting layer is formed by mixing agreen organic light-emitting material, a red organic light-emittingmaterial, and a hole-type organic host material;

the organic sensitive material is one or two selected fromtris(acetylacetone)phenanthroline thulium andtris(acetylacetone)phenanthroline dysprosium; and

the organic sensitive material is 0.1 wt %-0.5 wt % of the electron-typeorganic host material.

According to this invention, the preparation method of the white organicelectroluminescent device is specifically as follows:

An anode layer on a substrate is firstly laser-etched into a stripelectrode, then ultrasonically cleaned sequentially with a cleaningliquid and deionized water for 10-20 min, and placed in an oven fordrying:

the dried substrate is placed in a pretreating vacuum chamber, subjectedto low-pressure plasma treatment for 1-10 min under a vacuum atmosphereof 8-15 Pa with a voltage of 350-500V, and then transferred to anorganic evaporation plating chamber;

upon the vacuum degree reaches 1-2×10⁻⁵ Pa, an anode modification layer,a hole transporting-electron blocking layer, a hole-dominatedlight-emitting layer, an electron-dominated light-emitting layer, and ahole blocking-electron transporting layer are sequentially evaporationplated on the anode layer; and the uncompleted device is transferred toa metal evaporation plating chamber, and a cathode modification layerand a metal cathode layer are sequentially evaporation plated under avacuum atmosphere of 4-6×10⁻⁵ Pa.

In the process of preparing the white organic electroluminescent deviceof this application, the deposition of the material is achieved bycontrolling the evaporation plating rate. According to this invention,the evaporation plating rate for the anode modification layer iscontrolled at 0.01-0.05 nm/s; the evaporation plating rates for the hostmaterials in the hole transporting-electron blocking layer, thehole-dominated light-emitting layer, the electron-dominatedlight-emitting layer, and the hole blocking-electron transporting layerare controlled at 0.05-0.1 nm/s; the evaporation plating rate for theorganic sensitive material is controlled at 0.00005-0.0005 nm/s; theevaporation plating rate for the green organic light-emitting materialis controlled at 0.0025-0.01 nm/s; the evaporation plating rate for theblue organic light-emitting material is controlled at 0.004-0.025 nm/s;the evaporation plating rate for the red organic light-emitting materialis controlled at 0.0005-0.003 nm/s; the evaporation plating rate for thecathode modification layer is controlled at 0.005-0.05 nm/s; and theevaporation plating rate for the metal cathode layer is controlled at0.5-2.0 nm/s. Here, when the hole-dominated light-emitting layer isevaporation plated, the red organic light-emitting material, the greenorganic light-emitting material and the hole-type organic host materialare evaporation plated from different evaporating sources at the sametime, the weight ratio of the doped red organic light-emitting materialto the hole-type organic host material is allowed to be controlledbetween 1.000%-3.0%, and the weight ratio of the green organiclight-emitting material to the hole-type organic host material isallowed to be controlled between 5.0%-10.0%, by regulating theevaporation plating rates of these three materials. When theelectron-dominated light-emitting layer is evaporation plated, theorganic sensitive material, the blue organic light-emitting material,and the electron-type organic host material are evaporation plated fromdifferent evaporating sources at the same time, and the mass ratio ofthe doped organic sensitive material to the electron-type organic hostmaterial is allowed to be controlled between 0.1%-0.5% and the massratio of the doped blue organic light-emitting material to theelectron-type organic host material is allowed to be controlled between8.0%-25.0% by regulating the evaporation plating rates of these threematerials.

This application provides a white organic electroluminescent device. Inthe electron-dominated light-emitting layer of the white organicelectroluminescent device, a rare earth complex having a matched energylevel distribution, for Example Tm(acac)₃ or Dy(acac)₃phen, is selectedas the organic sensitive material, which has the function of a deepbinding center for charge carriers. This is advantageous to balance thedistribution of carriers and widen the range of light emission of thedevice, so that the light-emitting effectiveness of the device isimproved, the operating voltage of the device is reduced, the efficiencyattenuation of the device is delayed, and the service life of the deviceis improved. Furthermore, the organic sensitive material has a matchedtriplet energy, which has the function of an energy transfer ladder.This can accelerate the energy transfer from the host material to thelight-emitting material and alleviate the problem of light emission ofthe host material caused by insufficient capability of carrier captureof the light-emitting material. Therefore, the spectral stability of thedevice is improved, and the dependence of the properties of the deviceon the doping concentration of the light-emitting material is reduced.

In order to further understand this invention, the white organicelectroluminescent device and the preparation method thereof provided bythis invention are described in detail below in conjunction withExamples. The protection scope of this invention is not limited by thefollowing Examples.

As shown in FIG. 1, FIG. 1 is a structural schematic diagram of thewhite organic electroluminescent device of this invention, wherein 1 isa glass substrate, 2 is an anode layer, 3 is an anode modificationlayer. 4 is a hole transporting-electron blocking layer. 5 is ahole-dominated light-emitting layer, 6 is an electron-dominatedlight-emitting layer, 7 is a hole blocking-electron transporting layer,8 is a cathode modification layer, and 9 is a metal cathode layer.

Example 1

An ITO anode layer on an ITO glass was laser-etched into a stripelectrode, then ultrasonically cleaned sequentially with a cleaningliquid and deionized water for 15 min. and placed in an oven for drying.The dried substrate was then placed in a pretreating vacuum chamber, andthe ITO anode was subjected to a low-pressure plasma treatment for 3 minunder an atmosphere having a vacuum degree of 10 Pa with a voltage of400V and then transferred to an organic evaporation plating chamber. Inan organic evaporation plating chamber with a vacuum degree of 1-2×10⁻⁵Pa, a MoO₃ anode modification layer 3 having a thickness of 3 nm, a TAPChole transporting-electron blocking layer 4 having a thickness of 40 nm,a TcTa hole-dominated light-emitting layer 5 doped with PQ₂Ir(dpm) andIr(ppy)₃ having a thickness of 10 nm, a CzSi electron-dominatedlight-emitting layer 6 co-doped with Tm(acac)₃phen and FCNIrpic having athickness of 10 nm, and a TmPyPB hole blocking-electron transportinglayer 7 having a thickness of 40 nm were sequentially evaporated on theITO layer. Next, the uncompleted device was transferred to a metalevaporation plating chamber, and a LiF cathode modification layer 8having a thickness of 1.0 nm was evaporated under a vacuum atmosphere of4-6×10-Pa. Finally, a metal Al cathode layer 9 having a thickness of 120nm was evaporated on the LiF layer through a specially-made mask plateto prepare an organic electroluminescent device having a structure ofITO/MoO₃/TAPC/PQ₂Ir(dpm)2.6%):Ir(ppy)₃(7%)TcTa/Tm(acac)₃phen(0.2%):FCNIrpic(18%):CzSi/TmPyPB/LiF/Al.The evaporation plating rate for MoO₃ in the anode modification layer 3was controlled at 0.01 nm/s, the evaporation plating rate for TAPC inthe hole transporting-electron blocking layer 4 was controlled at 0.05nm/s, the evaporation plating rates for PQ₂Ir(dpm), Ir(ppy)₃ and TcTa inthe hole-dominated light-emitting layer 5 were controlled at 0.0013nm/s, 0.0035 nm/s and 0.05 nm/s respectively, the evaporation platingrates for Tm(acac)₃phen, FCNIrpic, and CzSi in the electron-dominatedlight-emitting layer 6 were controlled at 0.0001 nm/s, 0.0035 nm/s, and0.05 nm/s respectively, the evaporation plating rate for TmPyPB in thehole blocking-electron transporting layer 7 was controlled at 0.05 nm/s,the evaporation plating rate for LiF in the cathode modification layer 8was controlled at 0.01 nm/s, and the evaporation plating rate for Al inthe metal cathode layer 9 was controlled at 1.0 nm/s.

As shown in FIG. 2, FIG. 2 shows the curves of characteristics ofvoltage-current density-brightness of the white organicelectroluminescent device prepared in this Example. In FIG. 2, the ◯curve was a current density-voltage curve of the device, and the □ curvewas a brightness-voltage curve of the device. It can be seen from FIG. 2that the brightness of the device increased as the current density andthe drive voltage increased, the turn-on voltage of the device was 3.0volts, and the maximal brightness of 44899 candelas per square meter(cd/m²) of the device was obtained when the voltage was 9.4 volts andthe current density was 484.56 milliamperes per square centimeter(mA/cm²).

As shown in FIG. 3, FIG. 3 shows the curves of characteristics ofcurrent density-power efficiency-current efficiency of the white organicelectroluminescent device prepared in this Example. It can be seen fromFIG. 3 that the maximal current efficiency of the device was 61.32 cd/Aand the maximal power efficiency was 64.18 lm/nW.

As shown in FIG. 4, FIG. 4 shows a spectrogram of the white organicelectroluminescent device provided by this invention when the brightnesswas 20000 cd/m². It can be seen from FIG. 4 that the main peaks of thespectrum were located at 462 nanometers, 515 nanometers and 595nanometers. The color coordinate of the device was (0.331, 0.332).

Example 2

An ITO anode layer on an ITO glass was laser-etched into a stripelectrode, then ultrasonically cleaned sequentially with a cleaningliquid and deionized water for 15 min, and placed in an oven for drying.The dried substrate was then placed in a pretreating vacuum chamber, andthe ITO anode was subjected to a low-pressure plasma treatment for 3 minunder an atmosphere having a vacuum degree of 10 Pa with a voltage of400V and then transferred to an organic evaporation plating chamber. Inan organic evaporation plating chamber with a vacuum degree of 1-2×10⁻⁵Pa, a MoO₃ anode modification layer 3 having a thickness of 3 nm, a TAPChole transporting-electron blocking layer 4 having a thickness of 40 nm,a mCP hole-dominated light-emitting layer 5 doped with PQ₂Ir(dpm) andIr(ppy)₃ having a thickness of 10 nm, a CzSi electron-dominatedlight-emitting layer 6 co-doped with Tm(acac)₃phen and FCNIrpic having athickness of 10 nm, and a TmPyPB hole blocking-electron transportinglayer 7 having a thickness of 40 nm were sequentially evaporated on theITO layer. Next, the uncompleted device was transferred to a metalevaporation plating chamber, and a LiF cathode modification layer 8having a thickness of 1.0 nm was evaporated under a vacuum atmosphere of4-6×10⁻⁵ Pa. Finally, a metal Al cathode layer 9 having a thickness of120 nm was evaporated on the LiF layer through a specially-made maskplate to prepare an organic electroluminescent device having thestructure ofITO/MoO₃/TAPC/PQ₂Ir(dpm)(2.4%):Ir(ppy)₃(6%):mCP/Tm(acac)₃phen(0.2%):FCNIrpic (18%):CzSi/TmPyPB/LiF/Al. The evaporation plating ratefor MoO₃ in the anode modification layer 3 was controlled at 0.01 nm/s,the evaporation plating rate of TAPC in the hole transporting-electronblocking layer 4 was controlled at 0.05 nm/s, the evaporation platingrates for PQ₂Ir(dpm), Ir(ppy)₃ and mCP in the hole-dominatedlight-emitting layer 5 were controlled at 0.0012 nm/s, 0.003 nm/s and0.05 nm/s respectively, the evaporation plating rates for Tm(acac)₃phen,FCNIrpic, and CzSi in the electron-dominated light-emitting layer 6 werecontrolled at 0.0001 nm/s, 0.009 nm/s, and 0.05 nm/s respectively, theevaporation plating rate for TmPyPB in the hole blocking-electrontransporting layer 7 was controlled at 0.05 nm/s, the evaporationplating rate for LiF in the cathode modification layer 8 was controlledat 0.01 nm/s, and the evaporation plating rate for Al in the metalcathode layer 9 was controlled at 1.0 nm/s.

The properties of the white organic electroluminescent device preparedin this example were tested. It was demonstrated by experimental resultsthat the device emitted white light at about 462 nanometers, 515nanometers, and 595 nanometers under the driving of a direct-currentpower supply. When the brightness was 20000 cd/m², the color coordinateof the device was (0.334, 0.336); and the color coordinate of the devicewas hardly changed as the operating voltage varied. The turn-on voltageof the device was 3.0 volts, and the maximal brightness of the devicewas 43588 cd/m². The maximal current efficiency of the device was 59.84cd/A and the maximal power efficiency was 62.63 lm/W.

Example 3

An ITO anode layer on an ITO glass was laser-etched into a stripelectrode, then ultrasonically cleaned sequentially with a cleaningliquid and deionized water for 15 min, and placed in an oven for drying.The dried substrate was then placed in a pretreating vacuum chamber, andthe ITO anode was subjected to a low-pressure plasma treatment for 3 minunder an atmosphere having a vacuum degree of 10 Pa with a voltage of400V and then transferred to an organic evaporation plating chamber. Inan organic evaporation plating chamber with a vacuum degree of 1-2×10⁻⁵Pa, a MoO₃ anode modification layer 3 having a thickness of 3 nm, a TAPChole transporting-electron blocking layer 4 having a thickness of 40 nm,a TcTa hole-dominated light-emitting layer 5 doped with PQ₂Ir(dpm) andIr(ppv)₃ having a thickness of 10 nm, a 26DCzPPy electron-dominatedlight-emitting layer 6 co-doped with Dy(acac)₃ and FCNIrpic having athickness of 10 nm, and a TmPyPB hole blocking-electron transportinglayer 7 having a thickness of 40 nm were sequentially evaporated on theITO layer. Next, the uncompleted device was transferred to a metalevaporation plating chamber, and a LiF cathode modification layer 8having a thickness of 1.0 nm was evaporated under a vacuum atmosphere of4-6×10⁻⁵ Pa. Finally, a metal Al cathode layer 9 having a thickness of120 nm was evaporated on the LiF layer through a specially-made maskplate to prepare an organic electroluminescent device having thestructure of ITO/MoO₃/TAPC/PQ₂Ir(dpm)(2.6%):Ir(ppy)₃(7%):TcTa/Dy(acac)₃(0.2%):FCNIrpic(16%):26DCzPPy/TmPyPB/LiF/Al. The evaporation platingrate for MoO₃ in the anode modification layer 3 was controlled at 0.01nm/s, the evaporation plating rate for TAPC in the holetransporting-electron blocking layer 4 was controlled at 0.05 nm/s, theevaporation plating rates for PQ₂Ir(dpm), Ir(ppy)₃ and TcTa in thehole-dominated light-emitting layer 5 were controlled at 0.0013 nm/s,0.0035 nm/s and 0.05 nm/s respectively, the evaporation plating ratesfor Dy(acac)₃, FCNIrpic, and 26DCzPPy in the electron-dominatedlight-emitting layer 6 were controlled at 0.0001 nm/s, 0.008 nm/s, and0.05 nm/s respectively, the evaporation plating rate for TmPvPB in thehole blocking-electron transporting layer 7 was controlled at 0.05 nm/s,the evaporation plating rate for LiF in the cathode modification layer 8was controlled at 0.01 nm/s, and the evaporation plating rate for Al inthe metal cathode layer 9 was controlled at 1.0 nm/s.

The properties of the white organic electroluminescent device preparedin this example were tested. It was demonstrated by experimental resultsthat the device emitted white light at about 462 nanometers, 515nanometers, and 595 nanometers under the driving of a direct-currentpower supply. When the brightness was 20000 cd/m², the color coordinateof the device was (0.333, 0.339); and the color coordinate of the devicewas hardly changed as the operating voltage varied. The turn-on voltageof the device was 3.0 volts, and the maximal brightness of the devicewas 44108 cd/m². The maximal current efficiency of the device was 60.79cd/A and the maximal power efficiency was 63.63 lm/W.

Example 4

An ITO anode layer on an ITO glass was laser-etched into a stripelectrode, then ultrasonically cleaned sequentially with a cleaningliquid and deionized water for 15 min, and placed in an oven for drying.The dried substrate was then placed in a pretreating vacuum chamber, andthe ITO anode was subjected to a low-pressure plasma treatment for 3 minunder an atmosphere having a vacuum degree of 10 Pa with a voltage of400V and then transferred to an organic evaporation plating chamber. Inan organic evaporation plating chamber with a vacuum degree of 1-2×10⁻⁵Pa, a MoO₃ anode modification layer 3 having a thickness of 5 nm, a TAPChole transporting-electron blocking layer 4 having a thickness of 30 nm,a mCP hole-dominated light-emitting layer 5 doped with Ir(ppy)₂(acac)and Ir(btp)₂(acac) having a thickness of 15 nm, a 26DCzPPyelectron-dominated light-emitting layer 6 co-doped with Tm(acac)₃phenand FIr6 having a thickness of 15 nm, and a 3TPYMB holeblocking-electron transporting layer 7 having a thickness of 35 nm weresequentially evaporated on the ITO layer. Next, the uncompleted devicewas transferred to a metal evaporation plating chamber, and a LiFcathode modification layer 8 having a thickness of 1.1 nm was evaporatedunder a vacuum atmosphere of 4-6×10⁻⁵ Pa. Finally, a metal Al cathodelayer 9 having a thickness of 250 nm was evaporated on the LiF layerthrough a specially-made mask plate to prepare an organicelectroluminescent device having the structure ofITO/MoO₃/TAPC/Ir(ppy)₂(acac)(7%):Ir(btp)₂(acac)(2%):mCP/Tm(acac)₃phen(0.2%):FIr6(12%):26DCzPPy/3TPYMB/LiF/Al.The evaporation plating rate for MoO₃ in the anode modification layer 3was controlled at 0.01 nm/s, the evaporation plating rate for TAPC inthe hole transporting-electron blocking layer 4 was controlled at 0.05nm/s, the evaporation plating rates for Ir(ppy)₂(acac), Ir(btp)₂(acac)and mCP in the hole-dominated light-emitting layer 5 were controlled at0.0035 nm/s, 0.001 nm/s and 0.05 nm/s respectively, the evaporationplating rates for Tm(acac)₃phen, Fir6, and 26DCzPPy in theelectron-dominated light-emitting layer 6 were controlled at 0.0001nm/s, 0.006 nm/s, and 0.05 nm/s respectively, the evaporation platingrate for 3TPYMB in the hole blocking-electron transporting layer 7 wascontrolled at 0.05 nm/s, the evaporation plating rate for LiF in thecathode modification layer 8 was controlled at 0.01 nm/s, and theevaporation plating rate for Al in the metal cathode layer 9 wascontrolled at 1.0 nm/s.

The properties of the white organic electroluminescent device preparedin this example were tested. It was demonstrated by experimental resultsthat the device emitted white light at about 462 nanometers, 515nanometers, and 595 nanometers under the driving of a direct-currentpower supply. When the brightness was 20000 cd/m², the color coordinateof the device was (0.334, 0.335); and the color coordinate of the devicewas hardly changed as the operating voltage varied. The turn-on voltageof the device was 3.1 volts, and the maximal brightness of the devicewas 42175 cd/m². The maximal current efficiency of the device was 60.10cd/A and the maximal power efficiency was 60.88 lm/W.

Example 5

An ITO anode layer on an ITO glass was laser-etched into a stripelectrode, then ultrasonically cleaned sequentially with a cleaningliquid and deionized water for 15 min. and placed in an oven for drying.The dried substrate was then placed in a pretreating vacuum chamber, andthe ITO anode was subjected to a low-pressure plasma treatment for 3 minunder an atmosphere having a vacuum degree of 10 Pa with a voltage of400V and then transferred to an organic evaporation plating chamber. Inan organic evaporation plating chamber with a vacuum degree of 1-2×10⁻⁵Pa, a MoO₃ anode modification layer 3 having a thickness of 6 nm, a TAPChole transporting-electron blocking layer 4 having a thickness of 50 nm,a TCP hole-dominated light-emitting layer 5 doped with Ir(mppy)₃ andIr(piq)₃ having a thickness of 12 nm, a UGH2 electron-dominatedlight-emitting layer 6 co-doped with Tm(acac)₃phen and fac-Ir(Pmb)₃having a thickness of 16 nm, and a BmPyPhB hole blocking layer 7 havinga thickness of 45 nm were sequentially evaporated on the ITO layer.Next, the uncompleted device was transferred to a metal evaporationplating chamber, and a LiF cathode modification layer 8 having athickness of 1.1 nm was evaporated under a vacuum atmosphere of 4-6×10⁻⁵Pa Finally, a metal Al cathode layer 9 having a thickness of 240 nm wasevaporated on the LiF layer through a specially-made mask plate toprepare an organic electroluminescent device having the structure ofITO/MoO₃/TAPC/Ir(mppy)₃(8%):Ir(piq)₃(2.2%):TCP/Tm(acac)₃phen(0.3%):fac-Ir(Pmb)₃(18%):UGH2/BmPyPhB/LiF/Al.The evaporation plating rate for MoO₃ in the anode modification layer 3was controlled at 0.01 nm/s, the evaporation plating rate for TAPC inthe hole transporting-electron blocking layer 4 was controlled at 0.05nm/s, the evaporation plating rates for Ir(mppy)₃, Ir(piq)₃ and TCP inthe hole-dominated light-emitting layer 5 were controlled at 0.004 nm/s,0.00011 nm/s and 0.05 nm/s respectively, the evaporation plating ratesfor Tm(acac)₃phen, fac-Ir(Pmb)₃, and UGH2 in the electron-dominatedlight-emitting layer 6 were controlled at 0.00015 nm/s, 0.009 nm/s, and0.05 nm/s respectively, the evaporation plating rate for BmPyPhB in thehole blocking-electron transporting layer 7 was controlled at 0.05 nm/s,the evaporation plating rate for LiF in the cathode modification layer 8was controlled at 0.01 nm/s, and the evaporation plating rate for Al inthe metal cathode layer 9 was controlled at 1.2 nm/s.

The properties of the white organic electroluminescent device preparedin this example were tested. It was demonstrated by experimental resultsthat the device emitted white light at about 462 nanometers, 515nanometers, and 595 nanometers under the driving of a direct-currentpower supply. When the brightness was 20000 cd/m², the color coordinateof the device was (0.331, 0.332); and the color coordinate of the devicewas hardly changed as the operating voltage varied. The turn-on voltageof the device was 3.1 volts, and the maximal brightness of the devicewas 39876 cd/m². The maximal current efficiency of the device was 58.62cd/A and the maximal power efficiency was 59.37 lm/W.

Example 6

An ITO anode layer on an ITO glass was laser-etched into a stripelectrode, then ultrasonically cleaned sequentially with a cleaningliquid and deionized water for 15 min, and placed in an oven for drying.The dried substrate was then placed in a pretreating vacuum chamber, andthe ITO anode was subjected to a low-pressure plasma treatment for 3 minunder an atmosphere having a vacuum degree of 10 Pa with a voltage of400V and then transferred to an organic evaporation plating chamber. Inan organic evaporation plating chamber with a vacuum degree of 1-2×10⁻⁵Pa, a MoO₃ anode modification layer 3 having a thickness of 3 nm, a TAPChole transporting-electron blocking layer 4 having a thickness of 40 nm,a BSB hole-dominated light-emitting layer 5 doped with Ir(ppy)₂(m-bppy)and Ir(piq)₂(acac) having a thickness of 10 nm, a BCBPelectron-dominated light-emitting layer 6 co-doped with Tm(acac)₃phenand mer-Ir(pmb)₃ having a thickness of 10 nm, and a TPBi holeblocking-electron transporting layer 7 having a thickness of 40 nm weresequentially evaporated on the ITO layer. Next, the uncompleted devicewas transferred to a metal evaporation plating chamber, and a LiFcathode modification layer 8 having a thickness of 1.0 nm was evaporatedunder a vacuum atmosphere of 4-6×10⁻⁵ Pa. Finally, a metal Al cathodelayer 9 having a thickness of 120 nm was evaporated on the LiF layerthrough a specially-made mask plate to prepare an organicelectroluminescent device having the structure ofITO/MoO₃/TAPC/Ir(ppy)₂(m-bppy)(9%):Ir(piq)₂(acac)(3%):BSB/Tm(acac)₃phen(0.3%):mer-Ir(pmb)₃(25%):BCBP/TPBi/LiF/Al.The evaporation plating rate for MoO₃ in the anode modification layer 3was controlled at 0.01 nm/s, the evaporation plating rate for TAPC inthe hole transporting-electron blocking layer 4 was controlled at 0.05nm/s, the evaporation plating rates for Ir(ppy)₂(m-bppy), Ir(piq)₂(acac)and BSB in the hole-dominated light-emitting layer 5 were controlled at0.0045 nm/s, 0.00015 nm/s and 0.05 nm/s respectively, the evaporationplating rates for Tm(acac)₃phen, mer-Ir(pmb)₃, and BCBP in theelectron-dominated light-emitting layer 6 were controlled at 0.0003nm/s, 0.025 nm/s, and 0.1 nm/s respectively, the evaporation platingrate for TPBi in the hole blocking-electron transporting layer 7 wascontrolled at 0.08 nm/s, the evaporation plating rate for LiF in thecathode modification layer 8 was controlled at 0.005 nm/s, and theevaporation plating rate for Al in the metal cathode layer 9 wascontrolled at 0.5 nm/s.

The properties of the white organic electroluminescent device preparedin this example were tested. It was demonstrated by experimental resultsthat the device emitted white light at about 462 nanometers, 515nanometers, and 595 nanometers under the driving of a direct-currentpower supply. When the brightness was 20000 cd/m², the color coordinateof the device was (0.335, 0.341); and the color coordinate of the devicewas hardly changed as the operating voltage varied. The turn-on voltageof the device was 3.0 volts, and the maximal brightness of the devicewas 43122 cd/m². The maximal current efficiency of the device was 60.55cd/A and the maximal power efficiency was 63.38 lm/W.

The descriptions of the above Examples are only used to help theunderstanding of the method of the present invention and the core ideathereof. It is to be indicated that, with respect to the person skilledin the art, various improvements and modifications may also be made tothis invention without departing from the principle of this invention.These improvements and modifications also fall in the protection scopeof the claims of this invention.

The above descriptions of the disclosed Examples enable the skilledperson in the art to achieve or use this invention. Various amendmentsto these Examples will be apparent to those skilled in the art. Generalprinciples defined herein may be achieved in other examples withoutdeparting from the spirit or scope of this invention. Therefore, thisinvention will not be limited to these examples illustrated herein, butis to comply with the widest scope consistent with the principles andnovel features disclosed herein.

1. A white organic electroluminescent device, comprising: a substrate;an anode layer provided on the substrate; an anode modification layerprovided on the anode layer; a hole transporting-electron blocking layerprovided on the anode modification layer; a hole-dominatedlight-emitting layer provided on the hole transporting-electron blockinglayer; an electron-dominated light-emitting layer provided on thehole-dominated light-emitting layer; a hole blocking-electrontransporting layer provided on the electron-dominated light-emittinglayer; a cathode modification layer provided on the holeblocking-electron transporting layer; and a cathode layer provided onthe cathode modification layer; wherein the electron-dominatedlight-emitting layer is composed of an organic sensitive material, ablue organic light-emitting material, and an electron-type organic hostmaterial; the hole-dominated light-emitting layer is composed of a greenorganic light-emitting material, a red organic light-emitting materialand a hole-type organic host material; the organic sensitive material isone or two selected from tris(acetylacetone)phenanthroline thulium andtris(acetylacetone)phenanthroline dysprosium; and the organic sensitivematerial is 0.1 wt %-0.5 wt % of the electron-type organic hostmaterial.
 2. The white organic electroluminescent device according toclaim 1, wherein the content of the blue organic light-emitting materialis 8.0 wt %-25.0 wt % of the content of the electron-type organic hostmaterial.
 3. The white organic electroluminescent device according toclaim 1 or 2, wherein the blue organic light-emitting material is one ormore selected from bis((3,5-difluoro-4-cyanophenyl)pyridinato)picolinateiridium, bis(2,4-difluorophenylpyridinato)tetrakis(1-pyrazolyl)borateiridium, tris(1-phenyl-3-methylbenzimidazolin-2-ylidene-C,C2′) iridium,tris(1-phenyl-3-methylbenzimidazolin-2-ylidene-C,C2′) iridium,bis(2,4-difluorophenylpyridinato)(5-(pyridin-2-yl)-1H-tetrazolate)iridium,tris[(2,6-diisopropylphenyl)-2-phenyl-1H-imidazol[e]iridium,tris(1-phenyl-3-methylimidazolin-2-ylidene-C,C(2)′)iridium,tris(1-phenyl-3-methylimidazolin-2-ylidene-C,C(2)′)iridium,bis(1-phenyl-3-methylimdazolin-2-ylidene-C,C²′)(2-(2H-pyrazol-3-yl)-pyridine)iridium,bis(1-(4-methylphenyl)-3-methylimdazolin-2-ylidene-C,C²′)(2-(2H-pyrazol-3-yl)-pyridine)iridium,bis(1-(4-fluorophenyl)-3-methylimdazoline-2-ylidene-C,C²′)(2-(2H-pyrazol-3-yl)-pyridine)iridium,bis(1-(4-fluorophenyl)-3-methylimdazoline-2-ylidene-C,C²′)(2-(5-trifluoromethyl-2H-pyrazol-3-yl)-pyridine)iridium,tris(1,3-diphenyl-benzimidazolin-2-ylidene-C,C²′)iridium,bis(1-(4-fluorophenyl)-3-methylimdazoline-2-ylidene-C,C²′)(3,5-dimethyl-2-(1H-pyrazol-5-yl)pyridine)iridium,bis(1-(4-methylphenyl)-3-methylimdazolin-2-ylidene-C,C²′)(3,5-dimethyl-2-(1H-pyrazol-5-yl)pyridine)iridium,and tris(phenylpyrazole)iridium.
 4. The white organic electroluminescentdevice according to claim 1, wherein the electron-type organic hostmaterial is one or more selected from2,6-bis[3-(9H-9-carbazoyl)phenyl]pyridine,1,4-bis(triphenylsilyl)benzene, 2,2′-bis(4-(9-carbazoyl)phenyl)biphenyl,tris[2,4,6-trimethyl-3-(3-pyridinyl)phenyl]borane,1,3,5-tri[(3-pyridinyl)-3-phenyl]benzene,1,3-bis[3,5-di(3-pyridinyl)phenyl]benzene,1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene,9-(4-tert-butylphenyl)-3,6-bis(triphenylsilyl)-9H-carbazole, and9-(8-diphenylphosphoryl)-dibenzo[b, d]furan-9H-carbazole.
 5. The whiteorganic electroluminescent device according to claim 1, wherein the redorganic light-emitting material is 1.0 wt %-3.0 wt % of the hole-typeorganic host material, the green organic light-emitting material is 5.0wt %-10.0 wt % of the hole-type organic host material; the green organiclight-emitting material is one or more selected fromtris(2-phenylpyridine) iridium, bis(2-phenylpyridine)(acetylacetone)iridium, tris[2-(p-tolyl)pyridine]iridium,bis(2-phenylpyridine)[2-(diphen-3-yl)pyridine]iridium,tris(2-(3-paraxylene)pyridine iridium andtris(2-phenyl-3-methyl-pyridine) iridium, the red organic light-emittingmaterial is one or more selected frombis(2-phenylquinoline)-(2,2,6,6-tetramethyl-3,5-heptanedionate) iridium,bis(2-benzo[b]-2-thiophenyl-pyridine)(acetylacetonate) iridium,tris(1-phenylisoquinoline) iridium,bis(1-phenylisoquinoline)(acetylacetone) iridium,bis[1-(9,9-dimethyl-9H-fluoren-2-yl)-isoquinoline](acetylacetone)iridium, bis[2-(9,9-dimethyl-9H-fluoren-2-yl)-quinoline](acetylacetone)iridium, bis(2-phenylquinoline)(2-(3-tolyl)pyridine) iridium,tris[2-phenyl-4-methylquinoline]iridium,bis(phenylisoquinoline)(2,2,6,6-tetramethylhexane-3,5-dione) iridium,bis(2-methyldibenzo[f,h]quinoxaline)(acetylacetone) iridium, andbis[2-(2-methylphenyl)-7-methyl-quinoline](acetylacetone) iridium, andthe hole-type organic host material is one or more selected from4,4′-N,N′-dicarbazole-biphenyl, 1,3-dicarbazol-9-ylbenzene,9,9′-(5-(triphenylsilyl)-1,3-phenyl)bis-9H-carbazole,1,3,5-tris(9-carbazoyl)benzene,4,4′,4″-tris(carbazol-9-yl)triphenylamine, and1,4-bis(triphenylsilyl)biphenyl.
 6. The white organic electroluminescentdevice according to claim 1, wherein the material of the holetransporting-electron blocking layer is one or more selected from4,4′-cyclohexylidenebis[N,N-bis(4-methylphenyl)aniline],dipyrazino[2,3-f:2′,3′-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile,N4,N4′-di(naphthalene-1-yl)-N4,N4′-bis(4-vinylphenyl)biphenyl-4,4′-diamine,N,N′-bis(3-methylphenyl)-N,N′-bis(phenyl)-2,7-diamino-9,9-spirobifluorene,N,N,N′,N′-tetra-(3-methylphenyl)-3-3′-dimethylbenzidine,2,2′-bis(3-(N,N-di-p-tolylamino)phenyl)biphenyl,N,N′-bis(naphthalen-2-yl)-N,N′-bis(phenyl)benzidine,N,N′-bis(naphthalen-1-yl)-N,N′-diphenyl-2,7-diamino-9,9-spirobifluorene,N,N′-bis(3-methylphenyl)-N,N′-diphenyl-2,7-diamino-9,9-dimethylfluorene,N,N′-bis(naphthalen-1-yl)-N,N′-diphenyl-2,7-diamino-9,9-dimethylfluorene,N,N′-bis(3-methylphenyl)-N,N′-diphenyl-2,7-diamino-9,9-diphenylfluorene,N,N′-bis(naphthalen-1-yl)-N,N′-diphenyl-2,7-diamino-9,9-diphenylfluorene,N,N′-bis(naphthalen-1-yl)-N,N′-diphenyl-2,2′-dimethylbenzidine,2,2′,7,7′-tetrakis(N,N-diphenylamino)-2,7-diamino-9,9-spirobifluorene,9,9-bis[4-(N,N-bis-naphthalen-2-yl-amino)phenyl]-9H-fluorene,9,9-[4-(N-naphthalen-1-yl-N-anilino)-phenyl]-9H-fluorene,2,2′-bis[N,N-bis(4-phenyl)amino]-9,9-spirobifluorene,2,2′-bis(N,N-phenylamino)-9,9-spirobi fluorene,N,N′-diphenyl-N,N′-(1-naphthyl)-1,1′-biphenyl-4,4′-diamine, and4,4′-bis[N-(p-tolyl)-N-phenyl-amino]diphenyl.
 7. The white organicelectroluminescent device according to claim 1, wherein the material ofthe hole blocking-electron transporting layer is one or more selectedfrom tris[2,4,6-trimethyl-3-(3-pyridinyl)phenyl]borane,1,3,5-tri[(3-pyridinyl)-3-phenyl]benzene,1,3-bis[3,5-di(3-pyridinyl)phenyl]benzene, and1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene.
 8. The white organicelectroluminescent device according to claim 1, wherein the anodemodification layer has a thickness of 1-10 nm, the holetransporting-electron blocking layer has a thickness of 30-60 nm, thehole-dominated light-emitting layer has a thickness of 5-20 nm, theelectron-dominated light-emitting layer has a thickness of 5-20 nm, thehole blocking-electron transporting layer has a thickness of 30-60 nm,the cathode modification layer has a thickness of 0.8-1.2 nm, and thecathode layer has a thickness of 90-300 nm.
 9. A preparation method of awhite organic electroluminescent device, comprising the steps of:etching an anode layer on a substrate, and after drying, evaporationplating an anode modification layer, a hole transporting-electronblocking layer, a hole-dominated light-emitting layer, anelectron-dominated light-emitting layer, a hole blocking-electrontransporting layer, a cathode modification layer, and a cathode layer inturn on the anode layer, wherein a material of the electron-dominatedlight-emitting layer is composed of an organic sensitive material, ablue organic light-emitting material, and an electron-type organic hostmaterial; the hole-dominated light-emitting layer is composed of a greenorganic light-emitting material, a red organic light-emitting materialand a hole-type organic host material; the organic sensitive material isone or two selected from tris(acetylacetone)phenanthroline thulium andtris(acetylacetone)phenanthroline dysprosium; and the organic sensitivematerial is 0.1 wt %-0.5 wt % of the electron-type organic hostmaterial.
 10. The preparation method according to claim 9, wherein theevaporation plating rate for the anode modification layer is 0.01-0.05nm/s; the evaporation plating rates for the hole transporting-electronblocking layer, the host material in the hole-dominated light-emittinglayer, the host material in the electron-dominated light-emitting layer,and the hole blocking-electron transporting layer are 0.05-0.1 nm/s; theevaporation plating rate for the organic sensitized material in theelectron-dominated light-emitting layer is 0.00005-0.0005 nm/s; theevaporation plating rate for the blue organic light-emitting material inthe electron-dominated light-emitting layer is 0.004-0.025 nm/s; theevaporation plating rate for the red light-emitting material in thehole-dominated light-emitting layer is 0.0005-0.003 nm/s; theevaporation plating rate for the green organic light-emitting materialin the hole-dominated light-emitting layer is 0.0025-0.01 nm/s; theevaporation plating rate for the cathode modification layer is0.005-0.05 nm/s; and the evaporation plating rate for the cathode layeris 0.5-2.0 nm/s.
 11. The white organic electroluminescent deviceaccording to claim 2, wherein the blue organic light-emitting materialis one or more selected frombis((3,5-difluoro-4-cyanophenyl)pyridinato)picolinate iridium,bis(2,4-difluorophenylpyridinato)tetrakis(1-pyrazolyl)borate iridium,tris(1-phenyl-3-methylbenzimidazolin-2-ylidene-C,C2′) iridium,tris(1-phenyl-3-methylbenzimidazolin-2-ylidene-C,C2′) iridium,bis(2,4-difluorophenylpyridinato)(5-(pyridin-2-yl)-1H-tetrazolate)iridium,tris[(2,6-diisopropylphenyl)-2-phenyl-1H-imidazol[e]iridium,tris(1-phenyl-3-methylimidazolin-2-ylidene-C,C(2)′)iridium,tris(1-phenyl-3-methylimidazolin-2-ylidene-C,C(2)′)iridium,bis(1-phenyl-3-methylimdazolin-2-ylidene-C,C2′)(2-(2H-pyrazol-3-yl)-pyridine)iridium,bis(1-(4-methylphenyl)-3-methylimdazolin-2-ylidene-C,C2′)(2-(2H-pyrazol-3-yl)-pyridine)iridium,bis(1-(4-fluorophenyl)-3-methylimdazoline-2-ylidene-C,C2′)(2-(2H-pyrazol-3-yl)-pyridine)iridium,bis(1-(4-fluorophenyl)-3-methylimdazoline-2-ylidene-C,C2′)(2-(5-trifluoromethyl-2H-pyrazol-3-yl)-pyridine)iridium,tris(1,3-diphenyl-benzimidazolin-2-ylidene-C,C2′)iridium,bis(1-(4-fluorophenyl)-3-methylimdazoline-2-ylidene-C,C2′)(3,5-dimethyl-2-(1H-pyrazol-5-yl)pyridine)iridium,bis(1-(4-methylphenyl)-3-methylimdazolin-2-ylidene-C,C2′)(3,5-dimethyl-2-(1H-pyrazol-5-yl)pyridine)iridium,and tris(phenylpyrazole)iridium.